Environmental concerns and legislative mandates on emissions are increasing, therefore, an increase in efficiency and reduction in overall emissions for internal combustion engines is desired. One way to increase overall system efficiency is to bleed or divert a portion of pressurized air from an intake to the internal combustion engine into the inlet of an air compressor, reducing the overall work of the compressor for the same output. The use of pressurized fresh air to drive flow into the air tank is more reliable and takes less time to fill the tank than naturally aspirated compressors. However, this diversion affects the accuracy of the determination of the fresh airflow component of the charge flow to the intake of the engine during air compressor operation. Therefore, various control operations that use fresh airflow values for engine operation can be adversely affected and possibly result in an emissions spike and other adverse conditions during compressor operation. Therefore, further technological developments are desirable in this area.